everytime i am in 3 or 4 gear and out my foot down the revs go up to nearly 8000 revs and then drops back down but the car does not gain speed i think i may need a new clutch but was wondering roughly how much a new clutch will cost so i can get the money saved. its not under warranty its a 2003 reg. Also the oil light keeps coming on but there is plenty oil i think this may be a faulty sensor. PLEASE HELP!